1. Field of the Invention
The present invention relates to a method for inhibiting production of toxins from enteropathogenic Escherichia coli and butyric-acid bacteria used for the method. More particularly, the present invention relates to a method for inhibiting production of Vero toxins from EHEC SU 5053 (O157), a method for safely sterilizing enteropathogenic Escherichia coli and butyric-acid bacteria and butyric-acid bacteria containing pharmaceuticals to be used for the method.
2. Background Information
To administer an antibiotic to an individual who is infected with enteropathogenic Escherichia coli has been known hitherto as a method for sterilizing the enteropathogenic Escherichia coli.
Of the enteropathogenic Escherichia coli, some bacteria, e.g., EHEC SU 5053 (O157) can cause toxins produced in cells to be liberated when cells become extinct or when the number of toxins reach the permissible maximum. Among of others, some toxins are so dangerous that they can cause not only hemorrhagic diarrhea, but also hemolytic uremic syndrome, to destroy cell membranes, such as red blood cells, which may lead to death of an individual. To administer an antibiotic to an individual who is infected with such dangerous bacteria induces toxins to be liberated when the bacteria becomes extinct due to the antibiotic, and further the toxins liberated are accumulated in the body (particularly in the intestinal tract). For this reason, it is significantly dangerous to administer an antibiotic to an individual infected with such dangerous bacteria. Also, if the number of toxins have already reached the permissible maximum before the antibiotic is administered, the toxins are already in liberation, and accordingly it is further significantly dangerous to administer the antibiotic to such an individual infected with the bacteria in that condition.
It is known, on the other hand, that multiplication of EHEC SU 5053 (O157) is strongly inhibited by mixed culture of human intestine indigenous Escherichia coli with EHEC SU 5053 (O157) of a kind of enteropathogenic Escherichia coli (Cf. USHIJIMA, Tsuyoshi, "Difference in antagonism effects of resident clonic bacteria for enterohemorrhagic Escherichia coli in anaerobic continuous cultures mimic media of adult and breast-fed newborn", Medical and Biology, 134(5):149-154, 1997; USHIJIMA, Tsuyoshi, "Potent growth inhibition of enterohemorrhagic Escherichia coli and some other gram negative Escherichia coli endopatnogens by resident grew maximum level in anaerobic cultures", Medical and Biology, 134(2):39-44, 1997; USHIJIMA, Tsuyoshi, "Potent antagonism effect of resident Escherichia coli in human colon on enteropathogenic enterohemorrhagic Escherichia coli and", Medical and Biology 127(1):5-9, 1993; and USHIJIMA, Tsuyoshi, "Antagonism effects of human colonic bacteria on some entergathogenic Escherichia coli", Medical and Biology, 126(1):9-14, 1993).
However, if fosfomycin (a cell wall synthetic inhibitor), which is an antibiotic, is added to the culture solution, then a large amount of Vero toxins will be liberated in the culture solution when EHEC SU 5053 (O157) becomes extinct. This indicates that human intestine indigenous Escherichia coli serves to inhibit toxins produced in the enteropathogenic Escherichia coli EHEC SU 5053 (O157) from being liberated in the culture solution in the process of multiplication of the enteropathogenic Escherichia coli EHEC SU 5053 (O157), but will not serve to inhibit toxins produced in the enteropathogenic Escherichia coli from being liberated in the culture solution, if fosfomycin is added thereto.
Accordingly, there has been being desired a method for inhibiting bacteria, which can produce toxins when cells becomes extinct (e.g., EHEC SU 5053 (O157)), from producing toxins in an individual who is infected with such bacteria and further administering antibiotic to the individual safely, to sterilize the bacteria safely, and a pharmaceutical used for the method.
The present inventors have discovered that enteropathogenic Escherichia coli is considerably inhibited from producing toxins (Vero toxins, in particular) by inoculating butyric-acid bacteria into an area contaminated by the enteropathogenic Escherichia coli and in turn adding an antibiotic thereto. They also have discovered that enteropathogenic Escherichia coli is considerably inhibited from producing toxins and is safely sterilized also by inoculating butyric-acid bacteria into an area having human intestine indigenous Escherichia coli (hereinafter it is sometimes referred to as "human intestine indigenous E. coli) and contaminated by the enteropathogenic Escherichia coli and in turn adding an antibiotic thereto. Based on these discoveries, the present inventors have accomplished the present invention.